The present application relates to a measurement system, and a method and computer program for processing measurement data, particularly to a measurement system, method and computer program for use in pattern measurement or the like.
With development of a fine processing technique such as a semiconductor manufacturing technique for manufacturing a semiconductor for use in various circuits, a liquid crystal display and the like, a measurement system has rapidly advanced/developed for processing image data and numerical data which are obtained by measuring objects processed by the fine processing technique.
As shown in FIG. 8 which is a schematic diagram showing a conventional measurement system, a conventional measurement system 1 comprises a host computer 2 and a plurality of measurement apparatuses 4 and 5. The measurement apparatus 4 includes, for example, an image processing unit 8 which subjects a measurement result to image processing. The measurement apparatus 5 includes an image processing unit 9.
A user A individually issues a recipe with respect to the measurement apparatus 4 or 5, and allows the measurement apparatus 4 or 5 to individually execute a measurement process. A user B individually issues a recipe with respect to the measurement apparatus 5 or 4, and allows the measurement apparatus 5 or 4 to individually execute a measurement process. Here, the recipe refers to a setting file of a measurement sequence or a control parameter to each measurement apparatus, and the recipe includes a setting for image acquisition and that for measurement.
In the conventional measurement system 1, the individual user A or B prepares a predetermined recipe for the measurement to issue the recipe to the measurement apparatus 4 or 5. On receiving the recipe, the measurement apparatus 4 or 5 performs measurement in accordance with the recipe of the measurement issued by the measurement apparatus 4 or 5 to display the results. After the image processing unit 8 or 9 performs predetermined image processing in accordance with the recipe for acquiring the image, measurement data is displayed.
In FIG. 8, each user prepares the recipe using a recipe preparation program provided by the apparatus. When the prepared recipe is designated, and executed, an image or a numerical value of a measurement object pattern can be obtained, and the obtained image is measurement by the image processing executed in the apparatus. The measurement result can be stored in the apparatus or the host computer 2, and referred to. Thus, according to the conventional system, a series of procedure has to be constantly performed with respect to the measurement apparatus 4 or 5 which is a target in order to prepare the recipe, execute measurement of the acquired image, and obtain a predetermined result.
Since the measurement mentioned here is abstract, an example of the measurement will be described hereinafter. As the example, there is critical dimension measurement (CD measurement) of a fine pattern formed in steps of manufacturing the semiconductor, including a lithography step and an etching step. A conventional technique and problem will be described. A technical field to which the measurement is applied is not limited to the CD measurement. The technical field is applied as a user support system relating to a general measurement process of a production line in various other industrial fields. For example, in a semiconductor manufacturing line, it is possible to utilize a system by the present proposal even in misalignment measurement, film thickness measurement and the like. The system by the proposal is also usable in measurement of a linear width of a transistor in a line for manufacturing a thin film transistor (TFT) liquid crystal panel.
In order to evaluate a fine pattern of the semiconductor, the CD measurement is performed using a critical dimension scanning electron-beam microscope (CDSEM). In this CDSEM, measurement data of dimension or the like of each pattern portion is acquired based on a SEM image of a measurement target pattern. These measurement data is stored in a hard disc (HD) connected to the host computer or the like connected to an engineering workstation (EWS) or high-order communication. The user accesses the data to obtain a desired measurement result.
A program for executing a measurement algorithm provided by the apparatus is stored in the EWS of the apparatus. Therefore, the user who cannot be satisfied with the function basically provided by the apparatus requires extensions of apparatus software with respect to an apparatus manufacturer, and requests the manufacturer to handle the extensions. The user depends on the apparatus manufacturer in this conventional way, and large burdens are imposed on the user together with cost and time.
However, in recent years, requirements for the measurement have been remarkably diversified. There are increasingly users who cannot be satisfied with the functions provided with the apparatus mainly in a research development field, and the conventional way cannot catch up with the requirements in a conspicuous case. For example, in recent years, the users increase who demand for more sophisticated image analysis (image processing, image measurement) such as automatic production of a recipe for measuring a position requiring measurement, extracted by yield simulation based on a computer-aided design (CAD) layout, measurement of an optical proximity correction (OPC) shape of reticle, and roughness measurement of a line.
However, since all the users do not require the functions, the apparatus manufacturers hesitate to perform development, and there has not been a flexible type of apparatus capable of completely satisfying the requirements in the present situation. Furthermore, it is necessary to individually consider user's various tastes or local circumstances in a data visualizing function such as various data analysis and graph preparation, but it is actually unreasonable to handle all of them.
Thus, there are three demerits as follows in a case where the enhancement of the function of the measurement apparatus depends on the manufacturer of the apparatus. The first demerit is that user's problem has to be disclosed with respect to the apparatus manufacturer, but this is not preferable from a viewpoint of confidentiality in some case. As the second demerit, in a case where manufacturers' expectations do not agree with users' needs, the users need to give up their needs. Even if the needs are satisfied, much cost and time are required. That is, in a certain plant, it is impossible to develop a technique for solving a problem caused in the morning by the end of the day, and to adapt to the developed technique. As the third demerit, even in a case where a solution to the problem has been already opened by the user, it depends on the apparatus manufacturer's discretion whether or not to accept and incorporate the solution as the function of the apparatus.
In this conventional passive way in which the enhancement of the function of the apparatus depends on the manufacturer, the user cannot but wait for the solution on the manufacturer side. Therefore, it has been increasingly recognized that the user needs to perform the enhancement as much as possible. For example, the user directly accesses the stored image via a network, and executes the image processing by a user's local personal computer (PC) to output a desired result. As application for use in this image processing, commercial general-purpose software has limits in the function and performance. Therefore, application/software for exclusive use has been opened.
Also in these cases, there are three problems as follows. First, there is a problem that application for exclusive use is used only in a specific user's local environment, and cannot be easily shared by many users. Secondly, there is a problem that the performance of the application for exclusive use, for example, an execution speed largely depends on the user's PC environment. Thirdly, there is a problem that it is difficult to manage version of the exclusive-use application once installed in the local PC by improvement or the like, and user's confusion is easily caused in a case where a plurality of exclusive-use applications exist and use environments are not integrated.
Moreover, there is also a problem that user's convenience is deteriorated as follows. That is, although the measurement is executed in the user's local environment, it is still necessary to face a screen of the apparatus in preparing the measurement recipe for acquiring the image. There are apparatus manufacturers which prepare software for preparing an offline/recipe as an option. Even when the option is prepared, a trouble of entering a clean room to move to the apparatus is only saved, and a problem still remains that two types of software for the recipe preparation and the measurement have to be operated in separate computers.
Furthermore, to measure/process images acquired by measurement apparatuses manufactured by different apparatus manufacturers by the same measurement algorithm, a plurality of measurement recipes have to be prepared by separate software using a plurality of computers, and the trouble of the recipe preparation is large as compared with a trouble required for the measurement itself.
In Japanese Patent Application Laid-Open No. 9-151304, a smart hub apparatus has been described comprising: a plurality of manufacturing apparatuses for performing processes; a plurality of client computers for controlling the apparatuses; conveying means for conveying a processed processing object material to a post-process manufacturing apparatus from a preprocess manufacturing apparatus; a server computer which performs the process in response to request of the client computer; and a network connected to a plurality of client computers and the server computer, so that variance control is executed for each manufacturing apparatus. In Japanese Patent Application Laid-Open No. 2002-16599, a network measurement control system has been described in which network traffic is measured with a meter, and measured data is transmitted to a control server. The control server holds policy of quality guarantee control or the like of a communication service, and analyzes the measured data collected from the meter to transmit a control instruction to an object apparatus such as a router in accordance with the policy. The router executes control in accordance with the control instruction, and accordingly careful communication service quality guarantee control is possible in accordance with a situation of the network. In Japanese Patent Application Laid-Open No. 2002-203760, a system has been disclosed comprising: at least one remote workstation connected to a local area network station via a remote access link; and a test system connected to the local workstation via a link. The system is capable of remotely operating and monitoring the test system of a semiconductor, and receiving data remotely from the test system of the semiconductor to test a chip in a position far from a physical test device.
As described above, in the conventional measurement system, the specific user A or B prepares and issues the recipe with respect to the specific measurement apparatus 4 or 5, and the measurement apparatus 4 or 5 which has received the recipe executes the recipe issued to the apparatus. That is, in the conventional measurement system, a process between client/server cannot be performed with respect to a plurality of measurement apparatuses, and it has been general to issue individual recipes to the individual measurement apparatuses by the individual users. Therefore, there are some manufacturers which provide systems as options, the systems comprise exclusive-use workstations for preparing recipes, and the recipes are shared as databases among different measurement apparatuses.
However, the only apparatuses manufactured by the same manufacturer share the recipe, and there has been a problem that users having a plurality of apparatuses by different manufacturers cannot share the recipe. Furthermore, even in the measurement apparatuses by the same manufacturer, a measurement method which can be described in the recipe is executable only in a range supported by the measurement apparatus, and it has been impossible to realize more sophisticated image analysis (image processing and image measurement).
There has been a demand for a measurement system in which a logic process server is disposed between a plurality of client computers and a plurality of measurement apparatuses. Accordingly, the process between client/server in the measurement system is possible, the preparation of the recipe among a plurality of apparatuses is possible, and image data or numerical data can be processed altogether which are measurement results. There has also been a demand for a measurement system capable of supporting not only a laboratory for performing the measurement, a manager of a plant measurement line, and a process development engineer but also measurement in a mass-production plant.